

/**
 * 函数防抖
 */
 export function debounce(fn, delay) {
    // 记录上一次的延时器
    var timer = null;
    var delay = delay || 200;
    return function() {
      var args = arguments;
      var that = this;
      // 清除上一次延时器
      clearTimeout(timer)
      timer = setTimeout(function() {
          fn.apply(that,args)
      }, delay);
    }
  }

  /**
 * 函数节流
 */
export const throttle =  (fn, delay=300) => {
	let timer = true;
	return function(args) {
		let that = this;
		let _args = arguments;
		if(!timer){
		   return false;
		}
		timer = false;
		setTimeout(() => {
			fn.apply(that, _args)
			timer = true;
		}, delay)
	}
}

/** 
 * 时间戳格式化函数 
 * @param {string} format 格式 
 * @param {int} timestamp 要格式化的时间 默认为当前时间 
 * @return {string}   格式化的时间字符串 
 */
 export const formatDate =  function (format, timestamp){ 
  var a, jsdate=((timestamp) ? new Date(timestamp*1000) : new Date());
  var pad = function(n, c){
      if((n = n + "").length < c){
          return new Array(++c - n.length).join("0") + n;
      } else {
          return n;
      }
  };
  var txt_weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
  var txt_ordin = {1:"st", 2:"nd", 3:"rd", 21:"st", 22:"nd", 23:"rd", 31:"st"};
  var txt_months = ["", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]; 
  var f = {
      // Day
      d: function(){return pad(f.j(), 2)},
      D: function(){return f.l().substr(0,3)},
      j: function(){return jsdate.getDate()},
      l: function(){return txt_weekdays[f.w()]},
      N: function(){return f.w() + 1},
      S: function(){return txt_ordin[f.j()] ? txt_ordin[f.j()] : 'th'},
      w: function(){return jsdate.getDay()},
      z: function(){return (jsdate - new Date(jsdate.getFullYear() + "/1/1")) / 864e5 >> 0},
      // Week
      W: function(){
          var a = f.z(), b = 364 + f.L() - a;
          var nd2, nd = (new Date(jsdate.getFullYear() + "/1/1").getDay() || 7) - 1;
          if(b <= 2 && ((jsdate.getDay() || 7) - 1) <= 2 - b){
              return 1;
          } else{
              if(a <= 2 && nd >= 4 && a >= (6 - nd)){
                  nd2 = new Date(jsdate.getFullYear() - 1 + "/12/31");
                  return date("W", Math.round(nd2.getTime()/1000));
              } else{
                  return (1 + (nd <= 3 ? ((a + nd) / 7) : (a - (7 - nd)) / 7) >> 0);
              }
          }
      },
      // Month
      F: function(){return txt_months[f.n()]},
      m: function(){return pad(f.n(), 2)},
      M: function(){return f.F().substr(0,3)},
      n: function(){return jsdate.getMonth() + 1},
      t: function(){
          var n;
          if( (n = jsdate.getMonth() + 1) == 2 ){
              return 28 + f.L();
          } else{
              if( n & 1 && n < 8 || !(n & 1) && n > 7 ){
                  return 31;
              } else{
                  return 30;
              }
          }
      },
      // Year
      L: function(){var y = f.Y();return (!(y & 3) && (y % 1e2 || !(y % 4e2))) ? 1 : 0},
      //o not supported yet
      Y: function(){return jsdate.getFullYear()},
      y: function(){return (jsdate.getFullYear() + "").slice(2)},
      // Time
      a: function(){return jsdate.getHours() > 11 ? "pm" : "am"},
      A: function(){return f.a().toUpperCase()},
      B: function(){
          // peter paul koch:
          var off = (jsdate.getTimezoneOffset() + 60)*60;
          var theSeconds = (jsdate.getHours() * 3600) + (jsdate.getMinutes() * 60) + jsdate.getSeconds() + off;
          var beat = Math.floor(theSeconds/86.4);
          if (beat > 1000) beat -= 1000;
          if (beat < 0) beat += 1000;
          if ((String(beat)).length == 1) beat = "00"+beat;
          if ((String(beat)).length == 2) beat = "0"+beat;
          return beat;
      },
      g: function(){return jsdate.getHours() % 12 || 12},
      G: function(){return jsdate.getHours()},
      h: function(){return pad(f.g(), 2)},
      H: function(){return pad(jsdate.getHours(), 2)},
      i: function(){return pad(jsdate.getMinutes(), 2)},
      s: function(){return pad(jsdate.getSeconds(), 2)},
      //u not supported yet
      // Timezone
      //e not supported yet
      //I not supported yet
      O: function(){
          var t = pad(Math.abs(jsdate.getTimezoneOffset()/60*100), 4);
          if (jsdate.getTimezoneOffset() > 0) t = "-" + t; else t = "+" + t;
          return t;
      },
      P: function(){var O = f.O();return (O.substr(0, 3) + ":" + O.substr(3, 2))},
      //T not supported yet
      //Z not supported yet
      // Full Date/Time
      c: function(){return f.Y() + "-" + f.m() + "-" + f.d() + "T" + f.h() + ":" + f.i() + ":" + f.s() + f.P()},
      //r not supported yet
      U: function(){return Math.round(jsdate.getTime()/1000)}
  };
  return format.replace(/[\\]?([a-zA-Z])/g, function(t, s){
  let ret;
      if( t!=s ){
          // escaped
          ret = s;
      } else if( f[s] ){
          // a date function exists
          ret = f[s]();
      } else{
          // nothing special
          ret = s;
      }
      return ret;
  });

}


// 判断arr是否为一个数组，返回一个bool值
function isArray (arr) {
    return Object.prototype.toString.call(arr) === '[object Array]';
}

// 深度克隆
function deepClone (obj) {
	// 对常见的“非”值，直接返回原来值
	if([null, undefined, NaN, false].includes(obj)) return obj;
    if(typeof obj !== "object" && typeof obj !== 'function') {
		//原始类型直接返回
        return obj;
    }
    let o = isArray(obj) ? [] : {};
    for(let i in obj) {
        if(obj.hasOwnProperty(i)){
            o[i] = typeof obj[i] === "object" ? deepClone(obj[i]) : obj[i];
        }
    }
    return o;
}